Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Internet resources in applied behavior analysis

Internet communication is becoming an important tool for both academic and clinical areas in psychology and behavior analysis. The Internet, a confederation of thousands of computer systems covering the entire globe (Plaud, 1996b), can significantly enhance behavior analysis in at least three major areas: (a) information exchange and communication among behavior analysts through list servers, (b) dissemination of empirical data and commentary through on-line journals and information servers, and (c) promotion of programs and services in behavior analysis. This commentary provides specific examples in each of these areas and addresses the basics of connecting to the Internet.     

Pavlov and the foundation of behavior therapy

The foundation, achievements, and proliferation of behavior therapy have largely been fueled by the movement's foundation in behavioral principles and theories. Although behavioral accounts of the genesis and treatment of psychopathology differ in the extent to which they emphasize classical or operant conditioning, the mediation of cognitive factors, and the role of biological variables, Pavlov's discovery of conditioning principles was essential to the founding of behavior therapy in the 1950s, and continues to be central to modern behavior therapy. Pavlov's reliance on a physiological model of the nervous system, sensible in the context of an early science of neurology, has had an implication for behavior therapists interested in the study of personality types. However, Pavlov's major legacy to behavior therapy was his discovery of "experimental neuroses," shown by his students Eroféeva and Shenger-Krestovnikova, to be produced and eliminated through the principles of conditioning and counter-conditioning. This discovery laid the foundation for the first empirically-validated behavior therapy procedure, systematic desensitization, pioneered by Wolpe. The Pavlovian origins of behavior therapy are analyzed in this paper, and the relevance of conditioning principles to modern behavior therapy is demonstrated. It is shown that Pavlovian conditioning represents far more than a systematic basic learning paradigm. It is also an essential theoretical foundation for the theory and practice of behavior therapy.     

Human behavioral momentum in a sample of older adults.

Behavioral momentum, the persistence of behavior under altered environmental contingencies, is derived from Newtonian physics and operant psychology. It has relevance to behavior analysis in terms of shaping strong behaviors and ensuring effective relapse prevention strategies in behavior modification and therapy. The authors investigated whether changing the operant schedule contingencies affects the responses of older humans to different stimuli when reinforcement density is systematically manipulated. Fifteen older adults participated in a computer study in which each of 2 keys in a baseline condition was associated with the same schedule of reinforcement and multiple variable intervals; the only difference was that 1 reinforcer was 10 times larger than the other. After 6 sessions, the authors changed the contingency schedule to either an extinction condition, a variable-time schedule, or a different variable-interval schedule, to assess how participants' responses persisted when reinforcement contingencies were systematically changed. The results were consistent with the predictions of behavioral momentum. The participants not only biased their responses in favor of the more densely reinforcing key, but when contingencies changed, they showed significantly biased responses. Results supported the conclusion that healthy older adults allocate their behaviors in a manner very sensitive to training stimuli conditions; consistent with the basic principles of behavioral momentum, they show a degree of resistance to change in their behaviors when the behavioral contingencies are altered.     

Relationship of Maudsley Obsessional-Compulsive Inventory Subscales with Negative Priming

The relationship between the 4 subscales (Checking, Cleaning, Doubting, Slowness) and total score of the Maudsley Obsessional-Compulsive Inventory (MOCI) and performance in a negative-priming task and a response-speed task in 102 undergraduates was examined. Only Cleaning subscale performance correlated with magnitude of negative priming. Performance on the Checking, Slowing, and Doubting subscales was not significantly related to the magnitude of negative priming. The not significant correlation between Checking score and negative priming magnitude supports the findings of Maki, O'Neill, and O'Neill (1994), who observed that compulsive checking (of, e.g., whether the stove is turned off) appeared to be unrelated to deficiencies in inhibitory control. The present results are not, however, consistent with the view that obsessive-compulsive characteristics (as measured by the MOCI) result in a disruption in and a reduction of inhibitory control (Enright & Beech, 1993).     

Institutional Review Board Issues Related to Special Populations

The present article begins with an introduction to the role of Institutional Review Boards (IRBs) in research activities in general and proceeds to issues IRBs face with relation to special populations, including children and terminally ill individuals, as well as developmentally disabled and cognitively impaired persons. A historical overview of research with these special populations is included, and the report concludes with a real-world example of how IRB-related issues with developmentally disabled and cognitively impaired individuals are discussed and resolved.     

Empirical support for the gender‐as‐culture hypothesis.

This investigation provided a test of the gender‐as‐culture, or ‘two cultures’, hypothesis proposed by Maltz and Borker (1982) to explain male/female differences in language use. Analysis of previous empirical investigations located 16 language features that had consistently been shown to indicate communicator gender and these were tested within the framework of the four dimensions of intercultural style proposed by Gudykunst and Ting‐Toomey (1998): direct versus indirect, succinct versus elaborate, personal versus contextual and instrumental versus affective. Study 1 provided preliminary evidence supporting the hypothesized language‐feature‐by‐dimension relationships (e.g., male directives were rated more direct and female uncertainty verbs more indirect). In Study 2, respondents rated multiple exemplars of the 16 language features, as well as 16 contrasting foil sentences, on all four dimensions, finding that nearly all of the variables fell on the hypothesized intercultural dimensions. In Study 3, respondents rated four sets of naturally occurring target sentences and matching foil sentences, representing all language variables, on their appropriate intercultural dimensions in order to establish dimensional polarity. Results across the three studies supported the hypothesized language feature‐by‐stylistic dimension relationship for 15 of the 16 variables: The 6 male language features were rated as more direct, succinct, personal, and instrumental, whereas 9 of the 10 female features were perceived as more indirect, elaborate, and affective. The findings demonstrate that gender preferences for language use function in ways that are consistent with stylistic preferences that distinguish national cultures.     

Signal Detection Analysis of Choice Behavior and Aging

The primary research question was whether older adults respond to the contingencies of reinforcement such that they allocate their behavior as predicted by the reinforcement contingencies and discriminative stimuli programmed by the experimenters. Six subjects, ranging in age from 62 to 74 years, participated in 15 experimental sessions. Subjects were instructed to press the F1 key when they saw a white circle, and to press the F12 key when they saw a red letter A. Responses on the F1 key were reinforced on a variable interval (VI) 30-s schedule (i.e., a VI schedule of reinforcement with 11 arithmetically spaced intervals with a mean of 30 s); F12 key responses were reinforced on a VI 60-s schedule (i.e., a VI schedule of reinforcement with 11 arithmetically spaced intervals with a mean of 60 s). Reinforcers included monetary units (10 cents) and verbal praise. Results indicated positive effects of stimulus control of behavior. Collective false alarms and miss rates represented only 0.05% of the total responses. Also, two thirds of the subjects allocated behavior consistent with the second hypothesis that a denser reinforcement schedule (i.e., the VI 30-s) would cause subjects to respond more quickly to this condition. Implications of the present results for clinical studies of Alzheimer's Disease and dementia, as well as behavior modification strategies with aging individuals, are discussed.